Bladed wheels for compressors, turbines and the like



y 1961 E. A. STALKER 2,986,375

BLADED WHEELS FOR COMPRESSORS, TURBINES AND THE LIKE Filed Feb. 14, 19573 Sheets-Sheet 1 ATTORNEYS y 1961 E. A. STALKER 2,986,375

BLADED WHEELS FOR COMPRESSORS, TURBINES AND THE LIKE Filed Feb. 14, 195720"'| 33 3 Sheets-Sheet 2 INVENTOR.

EDWARD A. STALKER WMM%@ y 1961 E. A. STALKER 2,986,375

BLADED WHEELS FOR COMPRESSORS, TURBINES AND THE LIKE Filed Feb. 14, 1957s Sheet-Sheet 3 INVEN TOR.

EDWARD A. STALKER W M, M

ATTORNEYS United States Edward A. Stalker, Bay City, Mich., assignor toThe Stalker Corporation, a corporation of Michigan Filed Feb. 14, 1957,Ser. No. 640,199

6 Claims. (Cl. 25339) This invention relates to bladed rotary fluidmachines such as compressors and turbines.

An object of the invention is to provide an axial flow bladed wheel inwhich the blades are integral with a central disk and each blade isconnected to said disk in such a manner as to minimize distortion underthe action of centrifugal force acting on each blade.

Another object is to reduce the number of brazed joints in such a wheelto a minimum.

Other objects will appear from the description, appended claims andaccompanying drawings.

The above objects are accomplished by the means illustrated in theaccompanying drawings in which- Fig. 1 is a fragmentary axial sectionthrough a rotary fluid machine according to this invention;

Fig. 2 is a fragmentary front view of a bladed wheel of the machine ofFig. 1 including two interdigitating series of blades;

Fig. 3 is an axial view of a central disk and its integral blades;

Fig. 4 is an enlarged fragmentary axial view of a blade and theassociated portion of the central disk, before the blade is twisted;

Fig. 5 is a fragmentary radial view of a wheel rim with the blades insection at their root ends;

Fig. 6 is a fragment of a rim and blade on line 6-6 of Fig. 5;

Fig. 7 is a fragmentary axial section of a machine similar to Fig. 1showing an alternate form of blade neck;

Fig. 8 is an enlarged view of a fragment of a blade disk showing theneck flanges;

Fig. 9 is a section through a blade on line 99 of Fig. 8;

Fig. 10 is a radial view of a fragment of the rotor rim on line 1010 ofFig. 7; and

Fig. 11 is a perspective view of a rotor of Fig. 7 partly cut away toshow the interdigitation of the blades.

In US. Patent No. 2,613,910, issued October 14, 1952 to the presentinventor there is disclosed a sheet metal construction for bladed wheelswherein each blade is integral with -a central disk. The neck connectingeach blade to the central disk is twisted to place the root end of eachblade at the proper angle with respect to the plane of the disk.

In the present invention a series of wheels are assembledgas shown inFig. 1, each wheel including a pair of central disks with necks joiningthe individual blades. Each neck is formed between dies so that eachradially extending element of the neck is a straight line alongitsextent from the perimeter of the disk to the root secatent f) thewheel. Means are also disclosed for providing substantial fillets at theroot sections of the blades.

The wheel comprises the sets of blades 20 and 22, integral respectivelywith central disks 24 and 26 of the hub means 28, the two sets beingassembled face to face with the blades interdigitating to form the wheelas shown in Figs. 1 and 2. The blades 20 are connected to their disk 24by the necks 30 and 34 extending from the periphery 31 of the centraldisks 24 and 26 to the root sections 32 of the blades. These sectionsare at about the radial level of the rim 33. Blades 22 are connected inlike manner by the necks 34 to their disks 26.

The necks 30' and 34 are formed on dies to have straight elementsextending from the central disk to the root ends of the blades. That is,each neck may be considered as comprised of a series of straight lineside-byside elements represented by the series of dotted lines 3'5-42,Fig. 4, each of which extends from the perimeter 31 of the central diskto the root of its respective blade in a straight line. Then eachelement of the neck can carry its portions of the centrifugal load ofthe blade without elongation from a bow in the element. Were suchelements bowed along their length the blade would move outward as thecentrifugal load removed the bow.

The wheel hub means 28 comprises the central disks 24 and 26 and a rimmeans 33 which is comprised of the two rings 66 and 68 each of which hasan integral flange '69, 70 which together define the hub rim extendingbetween blades and from front to rear thereof. It also includes thefillet elements 71 and 72, Figs. 5 and 6.

The rings have registering notches and 82, Fig. 5, which in registrationdefine blade openings through which the blades extend in the generalradial direction. Each opening is preferably larger than the crosssection of the root end of the blade so that the fillet elements 71, 72can be inserted on each side of the root end of the blade. These filletelements may be solid, preferably being made of sintered metal powder,such as stainless steel or nickel for instance, so that they will absorbbraze material during a brazing operation and become essentially solidand bonded to the blades and rims, and preformed as shown in Fig. 6providing fillets which fay the side surfaces of the blades and theexterior surface of the rim. Such powder material after beingimpregnated provides a high damping effect against the vibration of theblades. The side legs of the rim means are secured to the central diskspreferably by braze material.

The rim prevents the blades from turning or untwisting under the actionof centrifugal force and since straight line elements connect the rootsections of the blades to the disks the tips of the blades arestabilized at a selected radius.

The blades may have any desired cross section impressed upon them. Fig.5 shows cambered blade sec tions whose central portions have parallelsides and faired nose and tail portions.

Fluid flows through the passages between the blades extending from thefront of the wheel to the back thereof in the downstream direction. Theleading edges are at the front of the wheel, i.e. at the right hand edgeas shown in Fig. 5.

In another form of'the invention shown in Figs. 7-11, a neck flange 104,106 is formed along each side of a neck extending from one neck to theadjacent one. Each neck 107, 108 preferably comprises straight lineelements as in Fig. 4. The neck flanges add greatly to the stiffness ofeach neck along their general radial extent and precludes a tendency forthe blades to move outward from changes in shape of the necks.

The neck flanges 104 of the rear central disk 26 extend rearward andthose (106) of the front central disk 24 extend forward. See Figs. 7 and11. This facilitates placing the central disks close together preferablyin contact with annular spacers 110 as shown. The necks connect theblades 112 and 114 to their respective disks. The blades may also haveblade sections varying in thickness along the greater parts of theirchord lengths.

The rotors are fixed between the end disks 120 and the cylindricalspacers 122 by the tie rods 124.

While the invention has been described as embodied in a compressor wheelit can be incorporated in like manner in turbine wheels.

It will now be clear that there has been provided a novel bladed wheelwherein the blade is integral with a central disk and has a twistedportion or neck joining the blade to the disk. The neck is made to be astrong structural member by imparting the necessary twist therein bydies so that there is no how along radial lines in elements extendingfrom the disk to the roots of the blades, the elements all beingstraight. Thus each neck is so formed over a major part of its widththat lines extending on the surface thereof from the disk to the rootsection in the general radial direction are essentially straight lines.This configuration eliminates any significant displacement of the bladeradially due to centrifugal force straightening out bowed elements.

While the forms of apparatus herein described con stitute preferredembodiments of the invention, it is to be understood that the inventionis not limited to these precise forms of apparatus, and that changes maybe made therein without departing. from the scope of the invention whichis defined in the appended claims.

What is claimed is:

1. In combination in an axial flow wheel for compressors, turbines andthe like having an axis of rotation, a blade disk having a plurality ofblades peripherally spaced thereabout and extending radially outwardthereof each said blade having a root section connected to said disk bya neck, said blades, said necks and said disk being formed integrallyfrom a single piece of sheet metal, said necks being twisted to positionsaid root sections of each said blade at a substantial angle withrespect to said disk, each said neck tending to untwist during saidrotation, and rim means positioned at said root sections extending fromfront to rear of said blades and therebetween, said rim means fittingclosely to said blade root ends restraining said necks from untwisting,each said neck being so formed over a major part of its width that linesextending on the surface thereof from said disk to said root section inthe general radial direction are essentially straight lines establishingsubstantially constant tip diameters for said blades during said highspeed rotation.

2. In combination in an axial flow wheel for compressors, turbines andthe like having an axis of rotation, a blade disk having a plurality ofblades peripherally spaced thereabout and extending radially outwardthereof each said blade having a root section connected to said disk bya neck, said blades, said necks and said disk being formed integrallyfrom a single piece of sheet metal, said wheel being adapted for highspeeds of rotation with accompanying flow of said fluid in a generallyaxial direction, said necks being twisted to position said root sectionsof each said blade at a substantial angle with respect to said disk,each said neck tending to untwist during said operation, rim meanspositioned at said root sections extending from front to rear of saidwheel and therebetwecn, said rim means fitting closely to said bladeroot ends restraining said necks from untwisting, each said neck beingso formed over a major part of its width that lines extending on thesurface thereof from said disk to said root section in the generalradial direction are essentially straight lines, and flanges at eachside of said necks extending from said root section substantially tosaid disk establishing substantially constant tip diameters for saidblades during said operation at said high speeds of rotation.

3. In combination in an axial flow wheel for compressors, turbines andthe like having an axis of rotation, a blade disk having a plurality ofblades peripherally spaced thereabout and extending radially outwardthereof each said blade having a root section connected to said disk bya neck, said blades, said necks and said disk being formed integrallyfrom a single piece of sheet metal, said wheel being adapted foroperation at high speeds of rotation with accompanying flow of saidfluid in a generally axial direction, said necks being twisted toposition said root sections of each said blade at a substantial anglewith respect to said disk, each said neck tending to untwist during saidoperation, rim means positioned at said rotor sections extending fromfront to rear of said wheel and therebetween, said rim means fittingclosely to said blade root ends restraining said necks from untwisting,each said neck elements being so formed over a major part of its widththat lines extending on the surface thereof from said disk to said rootsection in .the general radial direction are essentially straight lines,and flanges at each side of said necks each extending continuously fromsaid root section of a said blade radially inward along the perimeter ofsaid plate and radially outward along the adjacent said neckestablishing sub stantially constant tip diameters for said bladesduring said operation at said high speeds of rotation.

4. In combination in an axial flow wheel for compressors, turbines andthe like having an axis of rotation, a blade disk having a plurality ofblades peripherally spaced thereabout each connected to said disk by aneck, said blades, said necks and said disk being formed integrally froma single piece of sheet metal, said blades having blade surfaces androot sections for operation at high tip speeds with accompanying flow ofsaid fluid in a generally axial direction, said necks being twisted toposition said root sections of each said blade at a substantial anglewith respect to said disk, each said neck tending to untwist during saidoperation, and rim means positioned at said root sections extending fromfront to rear of said wheel and therebetween, said rim means fittingclosely to said blade root ends restraining said necks from untwisting,each said neck being so formed over a major part of its width that linesextending on the surface thereof from said disk to said root section inthe general radial direction are essentially straight lines.

5. In combination in an axial flow wheel for compressors, turbines andthe like having an axis of rotation, a blade disk having a plurality ofblades peripherally spaced thereabout each connected to said disk by aneck, said blades, said necks and said disk being formed integrally froma single piece of sheet metal, said blades having blade surfaces androot sections for operation at high tip speeds with accompanying flow ofsaid fiuid in a generally axial direction, each said neck being twistedto position each said root section of each said blade .at a substantialangle with respect to said disk, each said neck tending to untwistduring said operation, rim means positioned at said root sectionsextending from front to rear of said wheel, each said neck being soformed over a major part of its width that lines extending on thesurface thereof from said disk to said root section in the generalradial direction are essentially straight lines, and flanges at eachside of said necks extending from said root sections substantially tosaid disk establishing substantially constant tip diameters for saidblades during said operation at said high tip speeds.

6. In combination in an axial flow wheel for compressors, turbines andthe like defining an axis of rotation, a blade disk having a pluralityof blades peripherally spaced thereabout each connected to said disk bya neck, said blades, said necks and said disk being formed integrallyfrom a single piece of sheet metal, said blades having blade surfacesand root sections for operation at high tip speeds with accompanyingflow of said fluid in a generally axial direction, said necks beingtwisted to root sections substantially to said disk establishingsubposition said root sections of each said blade at a substantiallyconstant tip diameters for said blades during stantial angle withrespect to said disk, each said neck said operation at said high tipspeeds.

tending to untwist during said operation, rim means positioned at saidroot sections extending from front to rear 5 R fer nc Cit d i the fil fhi patent of said wheel, each said neck being so formed over a UNITEDSTATES PATENTS major part of its width that lines extending on thesurface thereof from said disk to said root section in the 1 3- Stalk1953 general radial direction are essentially straight lines, and2,678,537 Stalker May 13,

flanges at each side of said necks extending from said 10 2,801,071 'PJuly 30, 1957

